Biologists have two different methods for estimating the growth rate of a population of animals.
One is based on counting the number of animals in a photographic image, and the other is based on
a computer-calculated surface area of the animals in the image. (Larger animals are generally older
and contribute more to reproduction.) The scatterplot above shows the estimates of the Population
Growth Rate (PGR) for each method along with the line y = x . Which statement is true based on the
scatterplot?
A. The surface area method overestimates the Population Growth Rate.
B. The count method underestimates the Population Growth Rate.
C. Both methods overestimate the Population Growth Rate.
D. Both methods give accurate estimates of the Population Growth Rate.
E. There is not enough information to tell how well either method estimates the actual Population
Growth Rate.
- An infrared thermometer measures the surface temperature of an object from a distance. The
measurement errors for one particular model are approximately normally distributed with a mean of
0 degrees C and a standard deviation of 1.3 degrees C. If the temperature of an object is 20 degrees
C, what is the probability that the thermometer will report the temperature as less than 18 degrees
C?
A. 0.023
B. 0.062
C. 0.097
D. 0.903
E. 0.938 - A study was conducted to test a new style of keyboard in preventing repetitive stress disorders.
Volunteers who have had problems with such injuries were randomly assigned to use either a
traditional keyboard or the new design. A significance test was conducted with the alternative
hypothesis that a smaller proportion of those using the new keyboard will suffer injuries than those
using the traditional keyboard. The resulting P -value was 0.07. Which is a correct interpretation of
this P -value?
A. The null hypothesis should be rejected.
marvins-underground-k-12
(Marvins-Underground-K-12)
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